1. Field of the Invention
The present invention relates to an optometric apparatus for subjectively examining (measuring) refractive power and others of examinee's eyes.
2. Description of Related Art
There are known optometric apparatuses called “refractor” and “phoropter” for subjectively examining (measuring) refractive power and others of eyes of an examinee. These apparatuses are arranged to manually selectively dispose optical elements such as sphere lenses and cylinder lenses in front of the eyes of the examinee, who views optotypes or charts presented forward of his/her eyes through the disposed optical elements, to subjectively examine (measure) the refractive power and others based on for example how the optotypes or charts are visible to the examinee. Such subjective optometric apparatuses are often used in a dark room. Accordingly, an examiner has to illuminate the information such as power of the optical elements and other information indicated on the apparatus with a penlight or the like in order to visually recognize them. To avoid such troublesomeness, there has recently been proposed an apparatus provided with a function for illuminating the indicated optical element information (e.g., U.S. Pat. No. 5,281,984). In this apparatus, the optical element information is illuminated from inside by light from a light source built in the apparatus.
However, illumination by the light source that emits general white light can easily make the indicated optical element information visible, whereas it would cause a problem that the inside of the dark room is lightened.